Feed dog assembly, thread trimming mechanism and presser foot lifting mechanism for a sewing machine

Abstract

The application provides a feed dog assembly and thread cutting and presser foot lifting mechanism of a sewing machine, and particularly relates to the technical field of sewing machine manufacturing. The feed dog assembly of the application is driven by the up-down lifting power source and the front-rear feed power source, only the up-down lifting power source is used to perform the thread cutting and presser foot lifting actions of the thread cutting and presser foot lifting mechanism, the thread cutting and presser foot lifting actions are performed by the single up-down lifting power source, and the thread cutting and presser foot lifting actions are continuously performed after the up-down lifting power source and the front-rear feed power source jointly perform the feed action, the utilization rate of the power device of the sewing machine is improved, the intelligent control level of the power system of the sewing machine is further improved, the power source required by the thread cutting and presser foot lifting actions is saved, and the application has high popularization and application value.

Description

TECHNICAL FIELD

[0001] The application provides a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism of a sewing machine, and particularly relates to the technical field of sewing machine manufacturing. BACKGROUND

[0002] The feed dog is one of the essential parts of the sewing machine to realize the sewing work. The applicant previously proposed a feed dog assembly of a separate sewing machine, and the specific scheme is that the up-down lifting motor and the front-rear feed motor of the feed dog assembly apply a non-lateral swing source to the feed dog, the up-down lifting motor and the front-rear feed motor indirectly act on the feed dog to perform the feed action, the front-rear feed motor drives the rotating disc to drive the connecting rod, the connecting rod is movably connected to the eccentric position of the rotating disc, and the connecting rod movably connects the feed dog connecting frame. The up-down lifting motor and the front-rear feed motor transmit the swing source to the feed dog assembly, the feed dog assembly can be installed on the bottom thread mechanism and manufactured into a modularized product to be used on various sewing machines. In the above-mentioned sewing machine, the thread trimming and presser foot lifting devices need to be additionally installed, and the power for driving the above-mentioned thread trimming and presser foot lifting actions needs to be additionally installed, so that the manufacturing cost of the sewing machine is increased. SUMMARY

[0003] In view of the problem of increased manufacturing cost of the above-mentioned sewing machine, the application particularly provides a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism of a sewing machine to solve the above-mentioned defects, and the application is characterized in that the feed dog assembly, thread trimming mechanism, presser foot lifting mechanism, up-down lifting power source and front-rear feed power source are provided, the feed dog assembly is driven by the up-down lifting power source and the front-rear feed power source, the up-down lifting power source and the front-rear feed power source jointly act on the feed dog assembly to perform the feed action of the sewing machine, and the up-down lifting power source drives the thread trimming mechanism and the presser foot lifting mechanism to perform the thread trimming action and the presser foot lifting action after the feed action of the above-mentioned feed dog assembly is completed.

[0004] Preferably, the front-rear feed power source is provided with a crank mounted on the output shaft, the output shaft of the up-down lifting power source is provided with a synchronous pulley, the crank indirectly acts on the feed dog frame to realize the front-rear feed action of the feed dog assembly, the synchronous pulley indirectly acts on the multi-stage cam one and the multi-stage cam two to realize the up-down lifting feed action of the feed dog assembly, the front output shaft of the up-down lifting power source performs the thread trimming action of the thread trimming mechanism, and the rear output shaft of the up-down lifting power source performs the presser foot lifting action of the presser foot lifting mechanism.

[0005] Preferably, the crank mounted on the output shaft is hinged to the swing rod, the crank drives the swing rod to operate, the swing rod is hinged to the feed dog frame, the feed dog frame is provided with a support shaft, the support shaft is clearance-fitted on the feed dog frame, the support shaft extends out of the feed dog frame and extends to both ends of the support, and the feed dog frame operates in the support.

[0006] Preferably, a synchronous pulley is installed on the front output shaft of the up-and-down power source, the synchronous pulley connects the multi-stage cam one and the multi-stage cam two through a synchronous belt, the multi-stage cam one and the multi-stage cam two are respectively located at the two ends of the bottom of the support, and the multi-stage cam one and the multi-stage cam two have convex points one and two.

[0007] Preferably, the multi-stage cam one is fixed on the rotating shaft one, and the multi-stage cam two is fixed on the rotating shaft two, the rotating shaft one and the rotating shaft two are sleeved on the feed dog fixing support.

[0008] Preferably, the feed dog fixing support further has a limiting support one and a limiting support two which can fix the up-and-down power source and the back-and-forth feed power source, the feed dog fixing support further has limiting blocks one and two which are used to limit the running position of the feed dog frame and / or support, and the feed dog assembly further has a swing lever, and the feed dog fixing support has a swing hole.

[0009] Preferably, a thread cutting crank is installed on the front output shaft of the up-and-down power source, the thread cutting crank acts on a thread cutting fork lever, the thread cutting fork lever has a thread cutting lever and a return lever, the thread cutting crank has a shaft sleeve, the shaft sleeve is located between the thread cutting lever and the return lever, and the thread cutting action is realized by the thread cutting fork lever acting on the thread cutting end.

[0010] Preferably, the shaft sleeve of the thread cutting shaft sleeve pushes the thread cutting lever to perform thread cutting, the shaft sleeve of the thread cutting shaft sleeve pushes the return lever to perform thread cutting return, and the thread cutting lever and the return lever can be interchanged in the up-and-down position of the thread cutting fork lever.

[0011] Preferably, a presser foot lifting cam is installed on the rear output shaft of the up-and-down power source, the cam part of the presser foot lifting cam driven by the up-and-down power source acts on a presser foot lifting rod, and the presser foot lifting action is realized by the presser foot lifting rod acting on the presser foot end.

[0012] Preferably, a gear one is installed on the front output shaft of the up-and-down power source, the multi-stage cam one is installed on the rotating shaft one, the multi-stage cam two is installed on the rotating shaft two, the rotating shaft one and the rotating shaft two pass through the feed dog fixing support, the rotating shaft one and the rotating shaft two of the feed dog fixing support are provided with a gear four and a gear three, and the gear four and the gear three are engaged.

[0013] Preferably, a gear two is additionally installed behind the gear four of the rotating shaft one or the gear three of the rotating shaft two, the additionally installed gear two is engaged with the gear one, the gear one drives the gear two and drives the gear four and the gear three in parallel.

[0014] Compared with the prior art, the feed dog assembly of the present application is driven by the up-down lifting power source and the front-rear feed power source, fully embodies the feed dog assembly performing the feed function of the sewing machine, only uses the up-down lifting power source to perform the thread cutting action of the thread cutting mechanism and the presser foot lifting action of the presser foot lifting mechanism, realizes that the thread cutting action and the presser foot lifting action are performed by a single up-down lifting power source, and are continuously performed after the up-down lifting power source and the front-rear feed power source jointly perform the feed action, not only improves the utilization rate of the power device of the sewing machine, but also further improves the intelligent control level of the power system of the sewing machine, saves the power source required for the thread cutting action and the presser foot lifting action, greatly reduces the manufacturing cost of the sewing machine, and has high popularization and use value. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a global view of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0016] Figure 2 is a front view of the feed dog assembly of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0017] Figure 3 is a configuration diagram of the feed dog assembly of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0018] Figure 4 is an exploded view of the feed dog assembly of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0019] Figure 5 is a position diagram of the feed dog swing lever of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0020] Figure 6 is a bracket structure diagram of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application;

[0021] Figure 7 is a gear scheme diagram of the second embodiment of the feed dog assembly, the thread cutting mechanism and the presser foot lifting mechanism of the sewing machine of the present application.

[0022] Reference numerals: 10 feed dog assembly, 11 feed dog holder, 12 multi-stage cam one, 121 rotating shaft one, 13 multi-stage cam two, 131 rotating shaft two, 14 swing rod, 15 support shaft, 16 bracket, 161 protrusion one, 162 protrusion two, 163 swing hole, 164 limit block one, 165 limit block two, 166 limit bracket one, 167 limit bracket two, 18 swing rod, 20a thread cutting mechanism, 20b presser foot lifting mechanism, 20a presser foot lifting cam. 1. Lifting foot top rod 22. Thread cutting crank 23. Bushing 231. Thread cutting fork rod 24. Thread cutting rod 241. Return rod 242. Thread cutting end actuator 25. Up and down lifting power source 30. Front output shaft 31. Rear output shaft 32. Front and rear feeding power source 40. Output shaft 41. Crank 42. Synchronous pulley 51. Synchronous pulley two 52. Synchronous pulley three 53. Feeding tooth fixing bracket 6. Gear one 71. Gear two 72. Gear three 73. Gear four 74. Detailed Implementation

[0023] The following is in conjunction with the appendix Figures 1-7 The preferred embodiments of this application are described in detail so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of this application. These embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0024] Example 1

[0025] exist Figures 1-6 This application proposes a feed dog assembly, a thread cutting mechanism, and a presser foot lifting mechanism for a sewing machine, comprising a feed dog assembly 10, a thread cutting mechanism 20a, a presser foot lifting mechanism 20b, a vertical lifting power source 30, and a front and rear feed power source 40. The feed dog assembly 10 is jointly driven by the vertical lifting power source 30 and the front and rear feed power source 40. These two power sources work together to perform the feed dog action, enabling the feed dog assembly 10 to fulfill the essential feed function of a sewing machine. After the feed dog action is completed, the vertical lifting power source 30 drives the thread cutting mechanism 20a and the presser foot lifting mechanism 20b to perform the thread cutting and presser foot lifting actions, respectively. First, the front output shaft 31 of the vertical lifting power source 30 performs the thread cutting action of the thread cutting mechanism 20a; then, the rear output shaft 32 of the vertical lifting power source 30 performs the presser foot lifting action of the presser foot lifting mechanism 20b. This application utilizes the front and rear feed power source 40 of the feed dog assembly 10 to perform the presser foot lifting action and thread cutting action after the feed action is completed, thereby improving the power utilization rate of the sewing machine, eliminating the power required to perform the presser foot lifting action and thread cutting action, and significantly reducing the manufacturing cost of the sewing machine.

[0026] The output shaft 41 of the front and back feed power source 40 is provided with a crank 42. The output shaft 41 of the up and down lift power source 30 is provided with a synchronous pulley 51. The crank 42 indirectly acts on the feed dog holder 11 to realize the front and back feed action of the feed dog assembly 10. The synchronous pulley 51 indirectly acts on the multi-stage cam 1 12 and the multi-stage cam 2 13 to realize the up and down lift feed action of the feed dog assembly 10. The front and back feed action and the up and down lift feed action are performed simultaneously to realize the feed action of the sewing machine.

[0027] In the feed action angle area of the front and back feed power source 40, the crank 42 provided on the output shaft 41 is hinged to the swing rod 18. The crank 42 drives the swing rod 18 to rotate. The swing rod 18 is hinged to the feed dog holder 11 to generate the front and back swing source of the output shaft 41 to the feed dog holder 11. The support shaft 15 is arranged on the feed dog holder 11 and is clearance fitted on the feed dog holder 11. The support shaft 15 extends out of the feed dog holder 11 and extends to both ends of the bracket 16. The feed dog holder 11 operates in the bracket 16. The front and back feed power source 40 drives the crank 42 to make the swing rod 18 generate the front and back swing source of the feed dog holder 11.

[0028] The front output shaft 31 of the up and down lift power source 30 is provided with a synchronous pulley 51. The synchronous pulley 51 drives the synchronous pulley 2 52 and the synchronous pulley 3 53 through a synchronous belt to act on the multi-stage cam 1 12 and the multi-stage cam 2 13 to realize the up and down lift feed action of the entire feed dog assembly 10. The multi-stage cam 1 12 and the multi-stage cam 2 13 are arranged at both ends of the bottom of the bracket 16. The up and down lift power source 30 drives the synchronous pulley 2 52 and the synchronous pulley 3 53 in the power source feed action angle area. Specifically, the multi-stage cam 1 12 is fixed on the rotating shaft 1 121 and the multi-stage cam 2 13 is fixed on the rotating shaft 2 131. The rotating shaft 1 121 and the rotating shaft 2 131 are sleeved on the feed dog fixed bracket 6. The multi-stage cam 1 12 and the multi-stage cam 2 13 have a convex point 1 161 and a convex point 2 162. The convex point 1 161 and the convex point 2 162 are arranged to generate the up and down swing source of the bracket 16 and the entire feed dog assembly 10 under the drive of the up and down lift power source 30.

[0029] The feed dog assembly 10 of the present application is fixed on the feed dog fixing support 6, and further has a swing lever 14 in a cylindrical shape. The feed dog fixing support 6 has a swing hole 163, which provides a space for the swing lever 14 to move up and down, and the swing of the swing source of the multi-stage cam 1 and the multi-stage cam 2 is limited by the swing hole 163 of the feed dog fixing support 6. In addition, the feed dog fixing support 6 further has a limiting support 1 166 and a limiting support 2 167, which can fix the up and down lifting power source 30 and the front and back feed power source 40, and the limiting support 1 166, the limiting support 2 167 and the body of the feed dog fixing support 6 form an integral whole. The feed dog fixing support 6 further has a limiting block 1 164 and a limiting block 2 165, which are used to limit the running position of the feed dog holder 11 and / or the support 16, so that the feed dog assembly 10 has a fixed running structure.

[0030] After the above-mentioned feed motion of the sewing machine is completed, the up and down lifting power source 30 starts to perform the thread cutting motion and the presser foot lifting motion. The front output shaft 31 of the up and down lifting power source 30 is provided with a thread cutting crank 23, which acts on a thread cutting fork lever 24, and then the thread cutting fork lever 24 acts on a thread cutting end execution part 25 to realize the thread cutting motion. The thread cutting fork lever 24 has a thread cutting lever 241 and a return lever 242, and the thread cutting crank 23 has a shaft sleeve 231, which is located between the thread cutting lever 241 and the return lever 242, and the shaft sleeve 231 pushes the thread cutting lever 241 to perform thread cutting, and the shaft sleeve 231 pushes the return lever 242 to perform thread return. The above-mentioned thread cutting lever 241 and the return lever 242 can be interchanged in the up and down positions of the thread cutting fork lever 24, and the technical effects realized by them are the same.

[0031] The rear output shaft 32 of the above-mentioned up and down lifting power source 30 is provided with a presser foot lifting cam 21, and under the drive of the up and down lifting power source 30, the cam part of the presser foot lifting cam 21 acts on a presser foot lifting top lever 22, and then the presser foot lifting top lever 22 acts on a presser foot lifting end execution part to realize the presser foot lifting motion.

[0032] The above-mentioned feed motion, presser foot lifting motion and thread cutting motion are located at the running corners of the front and back feed power source 40, respectively, which are the feed motion corner area, the presser foot lifting motion corner area and the thread cutting motion corner area. The sequence of the sewing motions performed by the front and back feed power source 40 is feed motion, thread cutting motion and presser foot lifting motion. It is worth mentioning that after the sewing machine stops after completing the feed motion, the front and back feed power source 40 shifts the running corner to perform the thread cutting motion and the presser foot lifting motion, in other words, the feed motion, the presser foot lifting motion and the thread cutting motion do not overlap in the corner area of the running of the front and back feed power source 40, and after the machine stops, the thread is cut first and then the presser foot is lifted.

[0033] In the corner area of the feed motion, the crank 42 is hinged to the swing lever 18 to generate the feed motion of the feed dog holder 11. When the sewing is finished, the feed motion power source 40 leaves the corner area of the feed motion and enters the corner area of the presser foot lifting motion and the corner area of the thread cutting motion. Since the upper and lower lifting power source 30 contacts the idle arc surface of the multi-stage cam 1 and the multi-stage cam 2 under the support 16 in the corner area of the presser foot lifting motion and the corner area of the thread cutting motion, the upper and lower lifting power source 30 does not generate the upper and lower lifting motion of the support 16, and the feed motion power source 40 is in the stop state, thus the whole feed dog assembly 10 is stationary. Similarly, when the feed motion power source 40 operates in the corner area of the feed motion, the shaft sleeve 231 of the thread cutting crank 23 idles back and forth between the thread cutting lever 24 and the return lever 242, and the arc surface of the presser foot cam 21 idles back and forth with the presser foot lifting lever 22, thus the feed motion, the presser foot lifting motion and the thread cutting motion performed by the feed motion power source 40 do not affect each other, and the motions are clear and distinct.

[0034] Embodiment 2

[0035] The embodiment 2 is basically the same as the above-mentioned embodiment 1, and the difference is that the upper and lower lifting power source 30 implements the swing source of the feed dog assembly 10 in a different way. In the attached Figure 7 The upper and lower lifting power source 30 also implements the sewing motion of the feed dog assembly 10 in the form of gear transmission. The front output shaft 31 of the upper and lower lifting power source 30 is provided with a gear 1 71, the multi-stage cam 1 is installed on a rotating shaft 1 21, and the multi-stage cam 2 is installed on a rotating shaft 2 131. The rotating shaft 1 21 and the rotating shaft 2 131 pass through the feed dog fixing support 6, and the rotating shaft 1 21 and the rotating shaft 2 131 passing through the feed dog fixing support 6 are provided with a gear 4 74 and a gear 3 73, which are engaged. In this embodiment, the gear 4 74 of the rotating shaft 1 21 or the gear 3 73 of the rotating shaft 2 131 is additionally provided with a gear 2 72, which is engaged with the gear 1 71, and the gear 1 71 drives the gear 2 72 and drives the gear 4 74 and the gear 3 73.

[0036] Alternatively, the gear 1 71 is directly engaged with the gear 2 72, and the gear 2 72 is omitted, which can also achieve the above-mentioned technical effect. Under the drive of the upper and lower lifting power source 30, the front output shaft 31 provided with the gear 1 71 drives the rotating shaft 1 21 or the rotating shaft 2 131 through the additionally provided gear 2 72, which has the same technical effect of generating the swing source of the feed dog assembly 10.

[0037] The above merely provides the preferred embodiment of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structure or equivalent flowchart transformation based on the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A sewing machine having a feed dog assembly, a thread trimming mechanism and a presser foot lifting mechanism, having an up-and-down power source (30) and a forward-and-backward feed power source (40), characterized by, The feed dog assembly (10) is driven by the up-down lifting power source (30) and the front-back feed power source (40), the up-down lifting power source (30) and the front-back feed power source (40) jointly act on the feed dog assembly (10) to perform the feed action of the sewing machine; The front-back feed power source (40) has an output shaft (41) installed with a crank (42), the crank (42) is hinged to the swing rod (18), the crank (42) drives the swing rod (18) to operate, the swing rod (18) is hinged to the feed dog rack (11), the support shaft (15) is arranged on the feed dog rack (11) in clearance fit, the support shaft (15) extends out of the feed dog rack (11) and extends to both ends of the bracket (16), the feed dog rack (11) operates in the bracket (16), the front-back feed power source (40) drives the crank (42) to make the swing rod (18) and the feed dog rack (11) produce front-back movement swing source; The output shaft (41) of the up-down lifting power source (30) is installed with a synchronous pulley (51), the synchronous pulley (51) drives the synchronous pulley two (52) and the synchronous pulley three (53) to connect the multi-stage cam one (12) and the multi-stage cam two (13) through the synchronous belt, the multi-stage cam one (12) and the multi-stage cam two (13) are respectively arranged at both ends of the bottom of the bracket (16), the multi-stage cam one (12) and the multi-stage cam two (13) have the convex point one (161) and the convex point two (162), the convex point one (161) and the convex point two (162) are arranged to make the bracket (16) and the whole feed dog assembly (10) produce up-down lifting swing source under the drive of the up-down lifting power source (30); After the feed action of the above-mentioned feed dog assembly (10) is completed, the up-down lifting power source (30) drives the thread cutting mechanism (20a) and the presser foot lifting mechanism (20b) to perform the thread cutting action and the presser foot lifting action in sequence, the front output shaft (31) of the up-down lifting power source (30) performs the thread cutting action of the thread cutting mechanism (20a), and the rear output shaft (32) of the up-down lifting power source (30) performs the presser foot lifting action of the presser foot lifting mechanism (20b).

2. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 1, wherein, The multi-stage cam one (12) is fixed on the rotating shaft one (121), and the multi-stage cam two (13) is fixed on the rotating shaft two (131), the rotating shaft one (121) and the rotating shaft two (131) are sleeved on the feed dog fixed bracket (6).

3. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 2, wherein, The feed dog fixed support (6) also has a limiting support one (166) and a limiting support two (167) which fix the up-down lifting power source (30) and the front-back feed power source (40), the feed dog fixed support (6) also has a limiting block one (164) and a limiting block two (165) which are used to limit the running position of the feed dog frame (11) or support (16), the feed dog assembly (10) also has a swing lever (14), the feed dog fixed support (6) has a swing hole (163) which provides a space for the swing lever (14) to move up and down.

4. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 1, wherein, The front output shaft (31) of the up-down lifting power source (30) is installed with a thread trimming crank (23) which acts on a thread trimming fork lever (24), the thread trimming fork lever (24) has a thread trimming lever (241) and a return lever (242), the thread trimming crank (23) has a shaft sleeve (231) which is located between the thread trimming lever (241) and the return lever (242), and then the thread trimming fork lever (24) acts on a thread trimming end execution end (25) to realize thread trimming action.

5. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 4, wherein, The shaft sleeve (231) pushes the thread trimming lever (241) to execute thread trimming, and the shaft sleeve (231) pushes the return lever (242) to execute thread trimming return.

6. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 4, wherein, The rear output shaft (32) of the up-down lifting power source (30) is installed with a presser foot lifting cam (21), the cam part of the presser foot lifting cam (21) driven by the up-down lifting power source (30) acts on a presser foot lifting jack (22), and then the presser foot lifting jack (22) acts on a presser foot end execution end to execute presser foot lifting action.

7. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 1, wherein, The front output shaft (31) of the up-down lifting power source (30) is installed with a gear one (71), the multi-stage cam one (12) is installed on a rotating shaft one (121), the multi-stage cam two (13) is installed on a rotating shaft two (131), the rotating shaft one (121) and the rotating shaft two (131) pass through the feed dog fixed support (6), the rotating shaft one (121) and the rotating shaft two (131) of the feed dog fixed support (6) are installed with a gear four (74) and a gear three (73), and the gear four (74) and the gear three (73) are engaged.

8. The sewing machine having a feed dog assembly, thread trimming mechanism and presser foot lifting mechanism according to claim 7, wherein, The rear of the gear four (74) of the rotating shaft one (121) or the gear three (73) of the rotating shaft two (131) is additionally installed with a gear two (72), the additionally installed gear two (72) is engaged with the gear one (71), the gear one (71) drives the gear two (72) and drives the gear four (74) and the gear three (73) in parallel.

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